System and method of air pollution monitoring utilizing chemiluminescence reactions

ABSTRACT

An instrumental system and method for detecting and analyzing pollutant gases in the atmosphere, particularly sulfur dioxide, ozone, nitrogen dioxide, and nitric oxide utilizing the catalyzed chemiluminescence reaction of luminol (5-amino-2, 3-dihydro-1-4phthalazinedione) with hydrogen peroxide. Sampled air streams, after appropriate treatment by adsorption column, are reacted with surface films of luminol-hydrogen peroxide solutions to give continuous, real time analysis of pollutant gases. The chemiluminescence method of monitoring air pollutants utilizes five or six microreactors (channels) simultaneously which are monitored sequentially by a single photomultiplier. Channel monitoring is controlled by a rotary shutter which moves discretely from channel (microreactor) to channel. Quantitative analysis of the gaseous components of the atmosphere is obtained by comparison of the signals obtained from the separate channels with calibrated standards for each channel. Signal processing may utilize simple computer circuitry.

United States Patent Anderson et al.

[ Apr. 25, 1972 [54] SYSTEM AND METHOD OF AIR POLLUTION MONITORINGUTILIZING CHEMILUMINESCENCE REACTIONS [73] Assignee: Geomet,Incorporated, Rockville, Md.

[22] Filed: Aug. 14, 1970 [2]] Appl. No.: 63,844

[52] US. Cl ..250/71 R, 23/230 R, 23/252 R,

Primary Examiner-Morton J. Frome Attorney-David H. Semmes 57 ABSTRACT Aninstrumental system and method for detecting and analyzing pollutantgases in the atmosphere, particularly sulfur dioxide, ozone, nitrogendioxide, and nitric oxide utilizing the catalyzed chemiluminescencereaction of luminol (5-amino-2,

' 3-dihydro-l-4-phthalazinedi0ne) with hydrogen peroxide. Sampled airstreams, after appropriate treatment by adsorption column, are reactedwith surface films of luminolhydrogen peroxide solutions to givecontinuous, real time analysis of pollutant gases.

250/435 R 250/218 The chemiluminescence method of monitoring airpollutants [51] lnt.Cl. ;0lj 1/42 utilizes five or six microreactors(channels) simultaneously 5s 1 Field of Search ..250 71 R 71.5 R 33.3 uvwhich are .mmimred sequentially by a Single Plwmmumpliar- 250/435 R128/1. 356/96 51 23/230 Channel monitoring is controlled by a rotaryshutter which 350/3 moves discretely from channel (microreactor) tochannel. Quantitative analysis of the gaseous components of the atfmosphere is obtained by comparison of the signals obtained [56] Reerences Cited from the separate channels with calibrated standards foreach UNITED STATES PATENTS channel. Signal processing may utilize simplecomputer circuitr 3,359,973 12/1967 Hoffman ..2s0/71 R x y 3,457,4077/1969 Goldberg ..250/71 R 23 Claims, 8 Drawing Figures IO AMBIENT AlRMANIFOLD RESERVOIR easant PL l8 ASCARTE 26 (ZIN. DIAMETER) LUMlNOL-NoOHFeSO4 RESERVOIR CrOs FROM CELL EXHAUSTS 20 f 24 LIQUID AIR n VACUUMSEPARATOR V PUMP Cb zz PATENTEDAPR 25 I972 3,659,100

sum 1 UF 5 mm All his. motwm N b\| 229$ 12 05o: g cm wkwizxm 38 20E 59no. 5 295mm. 3 59m 10 2-65.54 E3255 3 S w moi my: 8 5E3? -F BzQBIQ O 22360 Eozmmmm \Swfi om 1 3 mm 2 m m5; #855 N. 39:24: m2 Ema? INVENTORSHOWARD H. ANDERSON RUDOLPH H. MOYER DONALD J. SIBBETT DAVID c.SUTHERLAND ATTORNEY PATEMTED APR 2 5 I972 SHEET 3 BF 5 SYSTEM AND METHODOF AIR POLLUTION MONITORING UTILIZING CI-IEMILUMINESCENCE REACTIONSBACKGROUND OF THE INVENTION Chemiluminescence emitted during oxidationof luminol is initiated by a number of chemical compounds. Hematin andporphyrins are known to catalyze the hydrogen peroxide-luminol reaction.Microorganisms, tissue cells, and materials containing suchiron-porphyrins as catalase may be detected and analyzed by utilizationof the reaction. Nerve gases, cyanide ion, sodium hypochlorite,potassium ferricyanide, and transition metal ions also initiate thereaction under appropriate conditions. In principal, initiation of anyof three classes of reaction mechanism may be operative: (a) peroxidedecomposition, (b) electron transfer reactions, and (c) formation ofexcited oxygen. Each of these initiating steps is followed by oxidationof luminol to aminophthallic acid, during which photon emission occurswith a spectral maximum in the range of 430 mp.. This emission of lightmay be utilized to follow or analyze the specified reactions.

This invention relates to the detection and quantitation of pollutantgases in the air: sulfur dioxide, ozone, nitrogen dioxide, and nitricoxide, as well as chlorine and otheras yet unrecognized gaseouscomponents, which are capable of initiating the reaction between luminoland hydrogen peroxide. The object of this invention is to provide asimple form 'of instrumentation for applying the well-establishedluminol-chemiluminescence technology to solving the problems associatedwith obtaining a nearly real-time analysis of pollutant gases. A relatedobject is to provide a sufficiently high degree of Sensitivity in theinstrumentation to measure all normal ambient levels of the pollutantgases. These concentrations are normally below 1 part-per-million byvolume and may routinely be as low as a few parts per billion inrelatively clean air. Since the luminol oxidation is uniquely sensitiveto very low pollutant levels appropriate utilization of this reaction,as defined herein, yields a novel, rapid, reliable, and extremelysensitive multiple-gas air monitoring system and method.

SUMMARY OF THE INVENTION The present invention, while broadly pertainingto detection and analyses of pollutant gases in the air which may bemoni tored separately by other methods, is particularly valuable becauseof the simplicity and sensitivity of the method involved. Another majoradvantage of this approach accrues from utilization of a singletechnique for determination of the four major gaseous pollutants. Thisestablishes a crosschecking or internal consistence capability which isnot attainable when differing techniques are employed for each of thepollutants. As a result, a much more compact monitoring system ispossible with attendant improvements in engineering design requirements.

An automatic Chemiluminescence Air Monitor in accordance with theinvention utilizes a single photomultiplier as a sensor for five or sixreactor cells or channels.

The instrumentation basically consists of an air supply fed via amanifold through limiting orifices into five or six /1 in. diameter(ID), or smaller, U-tube cells. At the entry to each cell, a smallquantity 0.1 ml./min.) of luminol-hydrogen peroxide solutions are addedto the air stream. The heterogeneous system (air-liquid) flows throughthe cells to a liquid gas separator (drop-out pot) and thence to waste.The sensor signal, in terms of light output, occurs at the surface ofthe gas-liquid interface in these cells. The sampled air passes throughthe vacuum pump while the liquid may be bled off from the separator orcontinuously removed. No pumps are required, the liquid and air. aretransported by the single vacuum pump acting through the cells andliquid-air separator lines. The ambient air streams passing to the cellsare processed in absorption columns in order to separate the gaseouscomponents which are measured.

Additional features, advantages and objects of the invention will bemore readily apparent from the following detailed description of anembodiment thereof when taken together with the accompanying drawings inwhich:

FIG. 1 is a schematic diagram of an automatic chemiluminescence airmonitor in-accordance with the invention indicating air and liquid flowpaths;

FIG. 2 is a schematic of a control and operating circuit for theinvention;

FIG. 3 is a view of a cell assembly for use in practicing the inventionas set up for five test channels, a portion being broken away forclarity of detail;

FIG. 4 is a sectional view taken on line 4--4 of FIG. 3;

FIG. 5 is a sectional view taken on line 5-5 of FIG. 3;

FIG. 6 is a schematic view of a filter holder and retainer for in-lineuse;

FIG. 7 is a sectional view of a filter retainer corresponding with FIG.6; and

FIG. 8 is a chart of detection sensitivity in accordance withutilization of the present invention.

Referring now more specifically to the drawings a concept of the broadprinciples of the invention is apparent from the schematic diagram ofthe monitor in FIG. 1 showing thevarious air and liquid flow paths. Theair supply is fed via an ambient air manifold generally indicated at 10through limiting orifices generally designated 12 into a plurality of,in the present instance five, preferably A diameter (I.D.) or smaller,U-tube cells indicated at 14. At the entry to each cell, a smallquantity (0.1 ml./min.) of luminol-hydrogen peroxide solutions fromreservoirs I6 and 18 thereof respectively are added to the air stream.The heterogeneous system (airliquid) flows through the cells to a liquidgas separator 20 in the nature of a drop-out pot and thence to waste asindicated at 22. A desired sensor signal, in terms of light output,occurs at the surface of the gas-liquid interface in these cells. Thesampled air passes through vacuum pump 24 while the liquid can be bledoff from the separator or continuously removed.

No pumps are required, the liquid and air being transported by a thesingle vacuum pump 24 acting through the cells 14 and liquid-airseparator (20) lines.

The ambient air streams passing to the cells are processed in adsorptioncolumns in order to separate the gaseous components which are measured.Five adsorbent columns 26, 28, 30, 32 and 34 are used. The nature andfunctions of these columns are indicated as follows:

Column Gaseous Outputs 26. Ascarite-Ferrous Nitric Oxide as NitrogenSulfate Chromic Oxide Dioxide 28. Ferrous Sulfate Nitric Oxide andChromic Oxide 30. Chromic Oxide Nitrogen Dioxide Ozone, NitrogenDioxide,

- and Nitric Oxide 32. Ferrous Sulfate Sulfur Dioxide 34. CharcoalFiltered air for background sample assembly is shown in greater detailin FIGS. 3-7 inclusive. The structure includes a photo-multiplier tubehousing assembly 38 having a photo-multiplier tube 40 mounted andcontained therein with appropriate connections including a high voltageconnector 42 and a signal out connector 44. Connected to housing 38 is areaction cell housing generally designated 46 by appropriate means whichmounts the various U-shaped testing cells 14 having a configuration asshown in FIG. 4. The reaction cell configurations are all similar in theapparatus. The cells are mounted through radial slots 48 leading toapertures 50 in the reaction cell housing. Interconnected into a leg ofeach test cell is an air tube 52 for introduction of ambient air fortesting and a luminol in tube 54 and hydrogen peroxide (H 0 in tube 56all of which enter through a teflon plug 58 sealing the end of the tube.The opposite end of the test cell is connected by tube60 for exhaust.The foregoing details are apparent from FIG. 4 of the drawings.Interposed between the test cells and photo-multiplier tube assembly isa neutral density filter generally 62 consisting of five filter segments62A, 62B, 62C, 62D and 62E supported in a filter holder 64 inconjunction with a filter retainer 66. Apertures 68 are provided in linein the filter holder and retainer to permit filter operation. Filterdetails are shown in FIGS. 6 and 7. A rotary shutter 70 is rotatablymounted on a shaft in bearing 72 and is provided with a shutter aperture74 having a light sealing O-ring 76 around the shutter aperture.

A drive motor 78 is provided for the rotary shutter and which preferablycan consist of a 10 r.p.m. synchronous, 110 v. AC, 60 Hz, 1 4; ismounted by motor support posts 80 of appropriate size and number. Amotor coupling generally indicated at 82 is operatively associated withthe rotorary shutter shaft. For the sequential phasing operationalmovement of the shutter for activating the various test cells a 1 10 v.AC solenoid 84 is attached by means of solenoid bracket 86 to the cellhousings. A five toothed ratchet wheel 88 is adapted for axial movementby solenoid 84 upon releasing index pawl 90 and relieving springpressure of solenoid return spring 92 on shutter O-ring 76. Thissolenoid return spring not only applies pressure on theshutter O-ringbut also resets the index pawl 90. The solenoid function is accomplishedthrough a solenoid lever 94 pivotably mounted on lever bracket 96 andwhich lever is bifurcated at its free end 98 for engagement through pins100 with ratchet wheel 88. A pawl block 102 mounts a pawl latch 104 withoperatively attached pawl spring 106. Details of the foregoing mechanismare clearly shown in FIGS. 3 and 5 of the drawings.

The foregoing described mechanism is designed for the chemiluminescencemethod of monitoring air pollutants utilizing five microreactors(channels) simultaneously by means of sequential monitoring by a singlephoto-multiplier. The channel monitoring is controlled by the rotaryshutter which moves discretely from channel to channel and aquantitative analysis of the gaseous components of the atmosphere isobtained by comparison of the signals obtained from the separatechannels with calibrated standards for each channel. The signalprocessing may utilize a simple computer circuitry. An operating circuitis schematically depicted in FIG. 2 of the drawings. The variousstations (five in number) are indicated on FIG. 5 of the drawings andinclude: I

Station 1 Filtered air (background reference) Station 2 Ozone Station 3Nitrogen dioxide (N0 Station 4 Nitric oxide and nitrogen dioxide (N0+NO) Station Sulfur dioxide (S0 The foregoing are indicated in gaseousoutputs.

Referring to FIG. 2 of the drawings operation of the photomultipliertube 40 and shutter wheel or shutter 70 are activated from a highvoltage power supply 108 and a shutter pawl timer 1 respectively.Signals from the photo-multiplier pass through signal out lead 112 to apre-amplifier 114 and thence to integrator amplifier 116, digitalvoltmeter 118, computer 120 to printer 122 for test result indication. Alow voltage power supply 124 feeds pre-amplifier 114 and integratoramplifier 116. Timer 110 is operatively interconnected with integratoramplifier 116 through start lead 126 and reset lead 128. Timer 110 isalso operatively connected with the digital voltmeter, computer andprinter respectively through print command lead 130 stop command lead132 and start command lead 134 as schematically illustrated in FIG. 2.

The following table shows the sequence of timed events for the fivechannel system shown and described herein. In essence, each cell will beread once every minute and the'integrated signal from each will be usedto calculate an analysis of each of the four gaseous constituents on theschedule, reference being made to the gaseous station details of FIG. 5.

0 Seconds Shutter Window at Station No. 1

m; (Bkgrd) 1 Seconds Start Integrator Transfer Signal to Digitalvoltmeter and/or Recorder or Computer Signal Off and Reset IntegratorRotate Window to Station No. 2

+ l 1 Seconds 12 Seconds 12 Seconds 13 Seconds Start Integrator 23Seconds Transfer Signal to Digital voltmeter,

etc.

+ 24 Seconds Rotate Window to Station No. 3

+ 25 Seconds Start Integrator Seconds Transfer Signal to Digitalvoltmeter,

REPEAT OPERATION For a six channel system for example repetitions willoccur every 10 seconds.

Subsequent to the foregoing time sequence repeat operation is initiated.

Operation of the invention will be more readily understood from resultsof sensitivity tests run to determine sensitivity of thechemiluminescence reaction to. the four gases: S0 0 N0 and NO.

All operations were conducteddynamically. In this operation, S0 N0 andNO were diluted in two steps: (1) gases from tank supplies were passedinto a surge or test chamber of 6-inch pipe where they were mixed withpurified air. (2) Various quantities (50 to 1,000 ml./min.) of thissupply were further diluted with filtered air in a second dilution step.

+ 36 Seconds 37 Seconds 47 Seconds 48 Seconds 49 Seconds 59 Seconds 60Seconds Utilization of this two-step procedure made available dilutionsupward from 19 p.p.b. by volume. Gas samples from the dilutor were feddirectly intothe chemiluminescence reactor cell where mixing withluminol and hydrogen peroxide solutions took place. Air was passedthrough the sample reaction tube at flow rates from 500 ml./min. to 6.7liters/min. The liquid reagents, usually 0/25 mg./ml. of luminol in 0.05N NaOH and 0.6 percent H O ,'were fed to the cells. The cell was placeddirectly next to the 2-inch (diameter) face of an EM! (9558)photo-multiplier tube which monitored the light output from thereaction. Liquid reagents were fed into the cell at rates from 0.1 to0.5 mL/minute each. The optical cell tubing 7 diameter was 0.187 in.,ID. Theliquid-gas mixture was pulled by a Neptune-Dyna pump into aseparation chamber, which in these tests was a separatory flask. Thegases were then exhausted from the pump into the room atmosphere.

For tests with pure gas components, air was passed through charcoalfilters before use. The main supply passed through an MSA CBR 86475filter assembly before diluting the pollutant test sample. A CMACanister Air Purifier, Serial C (Barneby- Cheney Corporation), was usedon the air source to the sample gas supply.

Tests of atmospheric air were conducted by pulling air directly from theroom into the reactor cells.

Teflon tubing was usedthroughout.

A set of results is indicated in FIG. 8, which is a plot of (S-N) involts vs. gas concentration in ppm (volume). In this terminology, S'isthe total signal in volts obtained from the photomultiplier under testconditions, and N is the background obtained with filtered air. Thus(S-N) is the signal arising from the gas sample flowing through thereactor cell. The background values, N, are normally in the range of 2-5 volts. In the cases of S0 N0 and NO, these tests were conducted bypassing the gases at a rate of 1.0 ml./min. into a wax-lined mixingchamber (602 1, volume) which was exhausted at a rate of 122.5liters/min. The diluted gas from the chamber was mixed with fresh,filtered air at a total flow rate of 2.0 liters/min. sample rates fromthe mixing chamber varied from 50 ml./min. to 1,000 ml./min. For ozone,the procedure was modified: filtered air was passed at various flowrates through a stainless container (1.2 l in volume) which contained aGE germicidal lamp (GE. No. 648-11) and then DETECTION OF S N0 AND 0 GasResponses/l0 p.p.b. 0;, [7.9 volts No visible light was emitted duringexposure to nitric oxide (NO). Nitric oxide analyses are obtained byconverting NO to N0 over the acidic chromium trioxide column, describedbelow. These results indicate that S0 0 and N0 are easily monitorable asis NO after conversion. Since under normal conditions, a signal changeof 0.5 volts is readily detectable, detection thresholds of the order ofthe following are estimated for the pure gases under these conditions.

DETECTION THRESHOLDS S0 0.3 p.p.b. (vol.)

N302 (and NO) 6.9

Detection thresholds and system sensitivity may be increased or adjustedby modification of the operating parameters in the cell: reagentconcentrations, air flow rate (linear velocity), and to a much lesserextent, liquid feed rate.

Separation of Signals from Gaseous Components In order to separate thesignals from a mixture of gases, a series of adsorbents were examinedfor utility in treatment of the air stream before entry into thereactor. These columns were tested initially with pure (diluted)components. Final column selections were tested in separation of thesignals from a relatively clean Pomona, California atmosphere.

Chromium trioxide, ferrous sulfate, and ascarite columns were utilizedto separate signals from the four components: S0 N0 0 and NO. Thefollowing table shows the functions of these columns.

Gaseous Component Gaseous Component The ferrous sulfate column wasprepared by dissolving 5.0 g. of op ferrous sulfate in 30 ml. of glassdistilled water and impregnating six 12.5 cm. Whatman GF/A glass fiberfilters (123 cm", each). After drying at 80 C., the sheets were cut intoA in. squares and packed into 8 in. drying tubes. After conditioning forfour hours by air passage at 2 liters/min, the column was used withoutfurther modification.

The chromium trioxide column was prepared according to the procedure ofM. Katz (*Air Pollution, ed. by AC. Stern, Academic Press, New York,1968, p. 90; BE. Saltzman and A.F. Wartburg, Anal. Chem., 37, 779(1965)). It was used in an 8-inch drying tube.

The following table compares some of the results obtained with the threecolumns separately. The air sampling rate utilized was 2.0 liters/min.These results form the basis for separation of signals from thecomponents passed by the columns.

COLUMN PERFORMANCES [Air sampling rate: 2 liters/minute] COLUl'INPERFORMANCES (onlinl|ed [Air sampling rate: 2 liters/minute] SulfurNitrogen Nitrogen Gas. dioxide Ozone dioxide oxide (V.) 0.0 250 46-6232-46 Ferrous sulfate:

Concentration (p.p.m.) 0.14 0.23 1.0 1.0 Signal, column out V. 85 250 54(1 Signal, column in (V. 82 0.1-1. 5 6-7 (1 Ascarite Concentration(p.p.m. 0.1-1 0. 23 l. 0 1.0 Signal, column out (v. 00 "250 66 (1Signal, column in (v.) 0. .2 0. 0 3 0 H201 at 0.6 percent Luminol at,0.25 mg./ml. in 0.05 N NaOH. "Photomultiplier saturation.

Signal Processing Five or six chemiluminescence signal inputs may beused to obtain the analysis for S0 N0 0 and NO. The following tableindicates the basis for the approach which was utilized in practical airtestsr' BASIS FOR GASEOUS ANALYSES Signal Adsorbent V1 Asearite*-ferroussulfatechromle oxide.

Measured gases N O (as N02)- Since CO2 does not interfere in thereaction, a number of basic adsorbents which are more stable may beused. Sodium carbonate on glass fiber paper has been effective andappears to have a much longer life.

The determination of V is optional and may be used to double check theresults.

Thus, by applying simple algebra, the signals from the individualcomponents may be isolated as follows:

An optional check on the independent results may be obtained from V Inorder to obtain solutions for the individual gas concentrations from thephotomultiplier output voltages, a calibration for each of thecomponents in the presence of the appropriate adsorbent column or seriesof columns is required. These calibrations yield gas concentration inthe air vs. photo-multiplier signal (S-N) in volts.

Analyses of Ambient Air In order to test the concepts involved inanalysis of ambient air, a series of tests have been conducted in theGeomet laboratory in Pomona, California. The air was sampled from withina large loft-type assembly area which had open loading doors leading tothe outside and two roof ports. The reagent system utilized comprised:l) luminol at 0.25 mg./ml. in 0.05 N Na OH. (This solution alsocontained 1.0 mg./ml. EDTA.) (2) Hydrogen peroxide at 1 percent. (Airwas sampled at a rate of 2 liters/minute.) Analyses were determined onthe basis of previously established calibrations.

During mornings, it was observed that total pollutants were very low,with ozone levels usually well below 0.1 p.p.m. Small amounts of NO(0.05-0.10 p.p.m.), N0 0.05 ppm) and S0 -0.0l 0.02 ppm) were observable.Commencing at about 11:00 am, ozone levels were observed to rise; NOlevels usually increased and S0 remained about the same. A typicalresult obtained midafternoon (3:00 pm.) was:

Ozone 0.26 p.p.m. NO 0.05 p.p.m. NO, 0.26 p.p.m. SO 0.03 p.p.m.

Summary of Apparent Technical Results a. Luminol chemiluminescence canbe applied to monitor c. The signal output for the chemiluminescencereaction varies with gaseous components, reagent concentrations, 1 flowconditions, and reactor configurations. Response sensitivity may beadjusted within wide ranges by appropriate selection of these physicalparameters. d. Under controlled conditions, without optimizing operatingparameters, 10 p.p.b. (volume), predictably will show the followingsignals:

Sulfur Dioxide 10.4 volts H Ozone 2.8 volts Nitrogen Dioxide 1.8 volts(and Nitric Oxide after conversion to NO,)

Minor changes can be effected in the method, system and apparatuswithout departing from the spirit and scope of the invention as definedin the appended claims.

We claim: I

1. A system for monitoring air pollution in gaseous form utilizingchemiluminescence reactions, comprising:

A. a chemiluminescence reactor cell;

B. means to sample ambient air for suspected pollutantv gases containedtherein and introduce the ambient air into said cell;

C. means to selectively react in said reactor cell the pollutant gasescontained in sampled ambient air with aqueous solutions of luminol andhydrogen peroxide which produce light during reaction with thepollutants in a two phase reaction including:

i. an aqueous phase containing luminol which is oxidized to producephotons; and

ii. a gas phase which reacts in the cell with luminol at the interfacebetween the gas and liquid surface; and

D. means to detect and quantitatively analyze the gaseous pollutantcontents developed in the reactions by produced light measurements.

2. 2. A system as claimed in claim 1, wherein the pollutant gases arereacted by direct reaction between the pollutant components and anaqueous mixture of luminol ('5-amin0-2-, 3-dihydro-l,4-phthalazinedione) and hydrogen peroxide.

3. A system as claimed in claim 2, and means to mix the aqueous chemicalreagents immediately prior to reaction with the gaseous air pollutants.

4. A system as claimed in claim 3, and means to produce requiredintimate contactbetween the pollutant gases and the light-producingchemical reagents in an optical cell.

5. A system as claimed in claim 4, and means to separate the componentsof the pollution gas mixture prior to entry into a plurality of reactioncells.

6. A system as claimed in claim 5, and means to monitor multiple gasstreams by a single photomultiplier sensor.

7. A system as claimed in claim 6, and means to simultaneously monitor amixture of air pollutants with a real-time readout or analysis.

8. A system as claimed in claim 7, and means to eliminate chemicalinterferences in the analysis of the separate pollution components.

9. A system as claimed in claim 8, and means to selectively view aseries of chemical reactor cells on a preselected time sequence.

10. A system as claimed in claim 9, and means to automati cally controlviewing time at each optical cell. 1

11. A system as claimed in claim 10, and means to extend the.sensitivity range of a photomultiplier sensor by introduction ofselected optical filtering materials between a light source and a lightsensor.

12. A system as claimed in claim 11, and means to introduce a series ofopticalfilters between the reaction cells and the photomultipliersensor. I

13. A method for monitoring gaseous pollutants in the air, includingsulfur dioxide, nitrogen dioxide, ozone, nitric oxide, chlorine, andother oxidants, comprising:

A. sampling ambient air for suspected pollutant gases contained therein;

B. selectively reacting in a chemiluminescence reactor cell various ofsaid pollutant gases in said ambient air with aqueous solutions .ofluminol and hydrogen peroxide which produce light during reaction withthe pollutants in a two phase reaction including:

i. an aqueous phase containing luminol which is oxidized to producephotons; and

ii. a gas phase which reacts in the cell with luminol at the interfacebetween the gas and liquid surface; and

C. detecting and quantitatively analyzing the pollutant contentsdeveloped in the reactions by produced light measurements.

14. A method as claimed in claim 1, wherein the pollutant gases arereacted by direct reaction between the pollutant components and anaqueous mixture of luminol (5-amino-2-, 3-dihydro-l 4-phthalazinedione)and hydrogen peroxide.

15. A method as claimed in claim 14, including intimately contacting thepollutant gases and the light producing chemical reagents in an opticalcell.

16. A method as claimed in claim 15, including separating the componentsof the pollution gas mixture prior to entry into a reaction cell.

171A method as claimed in claim-16, including monitoring multiple gasstreams in a single photomultiplier sensor.

18. A method as claimed in claim 17, including simultaneously monitoringa mixture of air pollutants with a real-time readout or analysis.

19. A method as claimed in claim 18, including eliminating chemicalinterferences in the analysis of the separate pollution components.

20. A method as claimed in claim 19, including selectively viewing aseries of reactions in chemical reactor cells on a pre-

2.
 2. A system as claimed in claim 1, wherein the pollutant gases arereacted by direct reaction betwEen the pollutant components and anaqueous mixture of luminol (5-amino-2-, 3-dihydro-1, 4-phthalazinedione)and hydrogen peroxide.
 3. A system as claimed in claim 2, and means tomix the aqueous chemical reagents immediately prior to reaction with thegaseous air pollutants.
 4. A system as claimed in claim 3, and means toproduce required intimate contact between the pollutant gases and thelight-producing chemical reagents in an optical cell.
 5. A system asclaimed in claim 4, and means to separate the components of thepollution gas mixture prior to entry into a plurality of reaction cells.6. A system as claimed in claim 5, and means to monitor multiple gasstreams by a single photomultiplier sensor.
 7. A system as claimed inclaim 6, and means to simultaneously monitor a mixture of air pollutantswith a real-time readout or analysis.
 8. A system as claimed in claim 7,and means to eliminate chemical interferences in the analysis of theseparate pollution components.
 9. A system as claimed in claim 8, andmeans to selectively view a series of chemical reactor cells on apreselected time sequence.
 10. A system as claimed in claim 9, and meansto automatically control viewing time at each optical cell.
 11. A systemas claimed in claim 10, and means to extend the sensitivity range of aphotomultiplier sensor by introduction of selected optical filteringmaterials between a light source and a light sensor.
 12. A system asclaimed in claim 11, and means to introduce a series of optical filtersbetween the reaction cells and the photomultiplier sensor.
 13. A methodfor monitoring gaseous pollutants in the air, including sulfur dioxide,nitrogen dioxide, ozone, nitric oxide, chlorine, and other oxidants,comprising: A. sampling ambient air for suspected pollutant gasescontained therein; B. selectively reacting in a chemiluminescencereactor cell various of said pollutant gases in said ambient air withaqueous solutions of luminol and hydrogen peroxide which produce lightduring reaction with the pollutants in a two phase reaction including:i. an aqueous phase containing luminol which is oxidized to producephotons; and ii. a gas phase which reacts in the cell with luminol atthe interface between the gas and liquid surface; and C. detecting andquantitatively analyzing the pollutant contents developed in thereactions by produced light measurements.
 14. A method as claimed inclaim 1, wherein the pollutant gases are reacted by direct reactionbetween the pollutant components and an aqueous mixture of luminol(5-amino-2-, 3-dihydro-1, 4-phthalazinedione) and hydrogen peroxide. 15.A method as claimed in claim 14, including intimately contacting thepollutant gases and the light producing chemical reagents in an opticalcell.
 16. A method as claimed in claim 15, including separating thecomponents of the pollution gas mixture prior to entry into a reactioncell.
 17. A method as claimed in claim 16, including monitoring multiplegas streams in a single photomultiplier sensor.
 18. A method as claimedin claim 17, including simultaneously monitoring a mixture of airpollutants with a real-time readout or analysis.
 19. A method as claimedin claim 18, including eliminating chemical interferences in theanalysis of the separate pollution components.
 20. A method as claimedin claim 19, including selectively viewing a series of reactions inchemical reactor cells on a pre-selected time sequence.
 21. A method asclaimed in claim 20, including automatically controlling viewing time ateach optical cell.
 22. A method as claimed in claim 21, includingextending the sensitivity range of a photomultiplier sensor byintroducing selected optical filtering materials between a light sourceand a light sensor.
 23. A method as claimed in claim 22, includingintroducing a series of optical filters between the reaction cells andthe photOmultiplier sensor.